1. Field of the Invention
This invention relates to blending heating fuel, and particularly to blending petroleum based fuel and vegetable oil.
2. Description of Background
As noted in Patent Application Publication 20050132642, Renewable vegetable derived oil for use as residential heating oil alternative has the potential of reducing the demand for non-renewable petroleum oil. In particular soybeans, which made up 57% of the total world wide oilseed production of 2002, have produced promising results in lab and field tests at Purdue University. United States farmers harvested 72.16 million acres of soybeans with an average yield of 37.8 bushels/acre (USDA-NASS). The United States soybean oil and meal production industry produced 21.81 billion pounds of oil in 2002 utilizing an estimated 57 million acres of soybeans (USDA-NASS). This is equivalent to 2.91 billion gallons of soybean oil ready for industrial, commercial, and food product use.
Moreover, also according Patent Application Publication 20050132642 to the United States Department of Energy's Energy Information Administration, nearly 8.1 million homes used petroleum heating oil, also known as No. 2 fuel oil, in the year 2002. The primary area of market potential is in the Northeast and Midwest with 75% and 10% of the total household respectively. This trend is also supported by the national residential fuel oil consumption data.
Although it has been promoted mostly as a fuel for diesel-powered vehicles, biodiesel is perfectly suited as an additive or replacement fuel in a standard oil-fired furnace or boiler. When used as a heating fuel, biodiesel is sometimes referred to as “biofuel” or “bioheat.” Made from new and used vegetable oils or animal fats, this fuel also has the advantage of being biodegradable, nontoxic and renewable: While fossil fuels took millions of years to produce, fuel stocks for biodiesel can be created in just a few months, and the plants grown to make biodiesel naturally balance the carbon dioxide emissions created when the fuel is combusted. What's more, the resulting fuel is far less polluting than its petroleum-based alternative.
As noted above, biodiesel is composed of long-chain fatty acids with an alcohol attached, an is often derived from vegetable oils. It is produced through the reaction of a vegetable oil with methyl alcohol or ethyl alcohol in the presence of a catalyst. Animal fats are another potential source. Commonly used catalysts are potassium hydroxide (KOH) or sodium hydroxide (NaOH). The chemical process is called transesterification which produces biodiesel and glycerin. Chemically, biodiesel is called a methyl ester if the alcohol used is methanol. If ethanol is used, it is called an ethyl ester. They are similar and currently, methyl ester is less expensive due to the lower cost for methanol. Biodiesel can be used in the pure form, or blended in any amount with diesel fuel for use in compression ignition engines.
However, it will be appreciated that crude vegetable oil and degummed vegetable oil blends are preferred over biodiesel blends since the vegetable oils are less expensive while providing similar heat content. It will be readily apparent that transesterified soybean oil, with its extra processing steps, will be more expensive than, for example, degummed soybean oil.
It will also be appreciated that owing to the different viscosities of the diesel fuel oil and the vegetable oil that there can be separation of the two blended oils over a period of time, leading to the fuel delivery system providing near pure vegetable oil to the heating system, thereby causing a malfunction in the heating system. Therefore there exists a need for initially blending the vegetable oil with the diesel fuel oil and keeping the oils blended over an extended period of time.